Project description:Hypericum perforatum L. (2n=4x=32) is an attractive model system for the study of aposporous apomixis. The earliest phenotypic features of aposporous apomixis in this species are the mitotic formation of unreduced embryo sacs from a somatic cell of the ovule nucellus and the avoidance of meiosis. In this research we addressed gene expression variation in sexual and apomictic plants, by focusing on the ovule nucellus, which is the cellular domain primarily involved into the differentiation of meiocyte precursors and aposporous embryo sacs. Gene expression analysis performed by RNAseq identified 396 differentially expressed genes and 1834 transcripts displaying phenotype-specific expression. Overall, our data suggest that phenotypic expression of aposporous apomixis is concomitant with the modulation of key genes involved in cell patterning, RNA splicing and RNA-directed DNA methylation.
Project description:Apomixis defines a number of reproductive strategies, which, unlike sexual reproduction, permit the inheritance of the maternal genome over generations without genetic recombination events. The key biological features of apomixis are the failure of meiosis (i.e., apomeiosis), the differentiation of unreduced embryo sacs and eggs, and their autonomous development in functional embryos through parthenogenesis and the formation of viable endosperm either via fertilization-independent means or following fertilization with a sperm cell (Koltunow and Grossniklaus 2003). Recently gained biological information has shown that H. perforatum is an attractive model system for the study of a naturally occurring form of asexual reproduction called aposporous apomixis, This research describes a global gene expression analysis of H. perforatum ovaries collected from sexual and aposporous plant accessions for the purpose of identifying genes and processes potentially associated with aposporous apomixis in this model species.
